Answer:
The three numbers are : 9, 9 and 18
Step-by-step explanation:
Since the mean is 12 the sum of the three numbers must be 36. This is because:
(let the three numbers be x y and z)
(x+y+z)/3=12
(x+y+z)=12*3
(x+y+z)=36
And since the mode is 9 two of the numbers must be 9.
So to find the third number;
9+9+z=36
z=36-18
z=18
